what is the theoretical yield of phosphoric acid and what is the percentage yield of phosphoric acid

Question

For the following reaction, 4.43 grams of tetraphosphorus decaoxide are mixed with excess perchloric acid (HClO4). The reaction yields 5.37 grams of phosphoric acid.

perchloric acid (HClO4) (aq) + tetraphosphorus decaoxide (s) phosphoric acid (aq) + dichlorine heptaoxide (l)

What is the theoretical yield of phosphoric acid ?
grams
What is the percent yield of phosphoric acid ?
%

Answer 1

12HClO₄ + P₄O₁₀ -> 4H₃PO₄ + 6Cl₂O₇  blanced equation

moles P4O10 used = 4.43 g x 1 mole/284 g = 0.0156 moles

Theoretical mass H3PO4 = 0.0156 moles P4O10 x 4 moles H3PO4/1 mol P4O10 x 98g/mol = 6.11 g 

Percent yield = 5.37 g/6.11 g (x100%) = 87.9%